Arachidonic Acid Ratio Research Articles

Effect of changing the lipid component of home parenteral nutrition in adults

The effect of different lipid emulsions (LEs) within the parenteral nutrition (PN) regimen of adult home PN (HPN) patients is not clear. This study investigated the effect of changing adult HPN patients from a soybean oil based LE (Intralipid) to either a fish oil containing LE (providing n-3 fatty acids) (SMOFLipid) or an olive oil based LE (ClinOleic). Thirty two adults receiving long-term HPN with Intralipid as the LE were transferred to receive either SMOFLipid (n=13) or ClinOleic (n=19) for 60 days. Liver function markers, cholesterol, triglycerides, a full profile of fatty acids, and several cytokines were measured at study entry and after 60 days. SMOFLipid did not affect liver function markers, blood lipids or plasma cytokines. ClinOleic lowered both gamma-glutamyltranspeptidase (P=0.044) and interleukin-8 (P=0.030) concentrations. Both LEs induced marked changes in the fatty acid profile of plasma. SMOFLipid resulted in significant decreases in the proportions of linoleic acid, several other n-6 fatty acids and the essential fatty acid (EFA) deficiency indicator mead acid and significant increases in the proportions of the n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. ClinOleic resulted in significant decreases in the proportions of some saturated fatty acids, linoleic acid, several n-6 fatty acids, all n-3 fatty acids and mead acid and a significant increase in the proportion of oleic acid. The ratio of mead to arachidonic acid in plasma was not altered by either SMOFLipid or ClinOleic. No patient had a mead acid to arachidonic acid ratio of >0.2, the cut-off used to indicate EFA deficiency. Both SMOFLipid and ClinOleic significantly alter the fatty acid profile of plasma in adult HPN patients previously using Intralipid. Neither LE induces EFA deficiency in these patients. SMOFLipid did not alter liver function markers or inflammation. In contrast, ClinOleic decreased some, though not all, markers of liver function and inflammation. SMOFLipid and ClinOleic may both be considered for use in adult HPN patients.

A regulatory insertion-deletion polymorphism in the FADS gene cluster influences PUFA and lipid profiles among Chinese adults: a population-based study

Arachidonic acid (AA) is the major polyunsaturated fatty acid (PUFA) substrate for potent eicosanoid signaling to modulate inflammation and thrombosis and is controlled in part by tissue abundance. Fatty acid desaturase 1 (FADS1) catalyzes synthesis of omega-6 (n-3) AA and n-3 eicosapentaenoic acid (EPA). The rs66698963 polymorphism, a 22-base pair (bp) insertion-deletion 137 bp downstream of a sterol regulatory element in FADS2 intron 1, mediates expression of FADS1 in vitro, as well as exerting positive selection in several human populations. The associations between the polymorphism rs66698963 and plasma PUFAs as well as disease phenotypes are unclear. This study aimed to evaluate the relation between rs66698963 genotypes and plasma PUFA concentrations and blood lipid profiles. Plasma fatty acids were measured from a single sample obtained at baseline in 1504 healthy Chinese adults aged between 35 and 59 y with the use of gas chromatography. Blood lipids were measured at baseline and a second time at the 18-mo follow-up. The rs66698963 genotype was determined by using agarose gel electrophoresis. Linear regression and logistic regression analyses were performed to assess the association between genotype and plasma PUFAs and blood lipids. A shift from the precursors linoleic acid and α-linolenic acid to produce AA and EPA, respectively, was observed, consistent with FADS1 activity increasing in the order of genotypes D/D to I/D to I/I. For I/I compared with D/D carriers, plasma concentrations of n-6 AA and the ratio of AA to n-3 EPA plus docosahexaenoic acid (DHA) were 57% and 32% higher, respectively. Carriers of the deletion (D) allele of rs66698963 tended to have higher triglycerides (β=0.018; SE: 0.009; P=0.05) and lower HDL cholesterol (β=-0.008; SE: 0.004; P=0.02) than carriers of the insertion (I) allele. The rs66698963 genotype is significantly associated with AA concentrations and AA to EPA+DHA ratio, reflecting basal risk of inflammatory and related chronic disease phenotypes, and is correlated with the risk of dyslipidemia. This trial was registered at chictr.org.cn as ChiCTR-EOC-17012759.

The Efficacy of MAG-DHA for Correcting AA/DHA Imbalance of Cystic Fibrosis Patients.

Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementations are thought to improve essential fatty acid deficiency (EFAD) as well as reduce inflammation in Cystic Fibrosis (CF), but their effectiveness in clinical studies remains unknown. The aim of the study was to determine how the medical food containing docosahexaenoic acid monoglyceride (MAG-DHA) influenced erythrocyte fatty acid profiles and the expression levels of inflammatory circulating mediators. We conducted a randomized, double blind, pilot trial including fifteen outpatients with Cystic Fibrosis, ages 18–48. The patients were divided into 2 groups and received MAG-DHA or a placebo (sunflower oil) for 60 days. Patients took 8 × 625 mg MAG-DHA softgels or 8 × 625 mg placebo softgels every day at bedtime for 60 days. Lipid analyses revealed that MAG-DHA increased docosahexaenoic acid (DHA) levels and decrease arachidonic acid (AA) ratio (AA/DHA) in erythrocytes of CF patients following 1 month of daily supplementation. Data also revealed a reduction in plasma human leukocyte elastase (pHLE) complexes and interleukin-6 (IL-6) expression levels in blood samples of MAG-DHA supplemented CF patients. This pilot study indicates that MAG-DHA supplementation corrects erythrocyte AA/DHA imbalance and may exert anti-inflammatory properties through the reduction of pHLE complexes and IL6 in blood samples of CF patients. Trial registration: Pro-resolving Effect of MAG-DHA in Cystic Fibrosis (PREMDIC), NCT02518672.

Association between the ratio of serum arachidonic acid to eicosapentaenoic acid and the presence of depressive symptoms in a general Japanese population: the Hisayama Study

BackgroundEpidemiological evidence suggests that fish consumption and intake of n-3 polyunsaturated fatty acids (PUFA)—namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—confer protection against depression. However, few studies have addressed the influence of the balance between n-3 PUFA and n-6 PUFA in the human body on depression. MethodsA total of 2,529 community-dwelling Japanese residents aged ≥ 40 years were assessed for depressive symptoms (defined as a score of 16 points or more on the Center for Epidemiologic Studies Depression Scale [CES-D]) in 2007. The serum arachidonic acid (AA) /EPA ratio and AA/DHA ratio were measured in frozen samples collected in 2002 and categorized into quartiles. The odds ratios (ORs) for the presence of depressive symptoms were calculated using a logistic regression model. ResultsThe prevalence of depressive symptoms was 4.3%. There was no significant association between either the serum AA/EPA ratio or AA/DHA ratio and the presence of depressive symptoms. However, subjects with the highest serum AA/EPA ratios (range: 3.28–13.3) had a 4.10 times (95%CI: 1.13–19.80) greater OR for the presence of depressive symptoms than those with the lowest ratios (0.30–1.65) after adjusting for confounding factors in the subgroup with high-sensitivity C-reactive protein (hs-CRP) ≥ 1.0 mg/L, while no clear association was observed in the subgroup with hs-CRP < 1.0 mg/L. LimitationsReverse causality is possible due to the cross-sectional study design. ConclusionsOur findings suggest that a higher serum AA/EPA ratio is associated with a greater likelihood of depressive symptoms in subjects with systemic inflammation in the general Japanese population.

ω-3 and ω-6 Fatty Acids Modulate Conventional and Atypical Protein Kinase C Activities in a Brain Fatty Acid Binding Protein Dependent Manner in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is a highly infiltrative brain cancer with a dismal prognosis. High levels of brain fatty acid binding protein (B-FABP) are associated with increased migration/infiltration in GBM cells, with a high ratio of arachidonic acid (AA) to docosahexaenoic acid (DHA) driving B-FABP-mediated migration. Since several protein kinase Cs (PKCs) are overexpressed in GBM and linked to migration, we explored a possible relationship between B-FABP and levels/activity of different PKCs, as a function of AA and DHA supplementation. We report that ectopic expression of B-FABP in U87 cells alters the levels of several PKCs, particularly PKCζ. Upon analysis of PKCζ RNA levels in a panel of GBM cell lines and patient-derived GBM neurospheres, we observed a trend towards moderate positive correlation (r = 0.624, p = 0.054) between B-FABP and PKCζ RNA levels. Analysis of PKC activity in U87 GBM cells revealed decreased typical PKC activity (23.4%) in B-FABP-expressing cells compared with nonexpressing cells, with no difference in novel and atypical PKC activities. AA and DHA modulated both conventional and atypical PKC activities in a B-FABP-dependent manner, but had no effect on novel PKC activity. These results suggest that conventional and atypical PKCs are potential downstream effectors of B-FABP/fatty acid-mediated alterations in GBM growth properties.

Impact of smoking history on the association between Eicosapentaenoic acid to arachidonic acid ratio and acute coronary syndrome: A multicenter cross-sectional study.

INTRODUCTIONThe association among smoking history, eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio and acute coronary syndrome (ACS) is yet to be investigated. The present study aimed to clarify the association between the EPA/AA ratio and ACS prevalence in patients admitted to the cardiology department based on their smoking history.METHODSWe enrolled 1733 patients from five cardiology divisions located in Tokyo, Japan, and measured their levels of polyunsaturated fatty acids, including EPA and AA, from January 2004 to May 2011. We assessed the association between the EPA/AA ratio and ACS in the subgroups stratified according to smoking history (never, former, current smokers) using multivariate logistic models.RESULTSA high EPA/AA ratio was significantly associated with decreased odds of ACS among patients without a smoking history (adjusted odds ratio AOR=0.20, 95% CI: 0.04–0.86) but not in patients with a smoking history (former smoker, AOR=1.50, 95% CI: 0.44–5.03; current smoker, AOR=3.73, 95% CI: 0.34–40.6).CONCLUSIONSThe EPA/AA ratio and ACS occurrence were found to be significantly associated in patients without a smoking history; however, no such association existed in patients with a smoking history.ABBREVIATIONSAA: arachidonic acid, ACS: acute coronary syndrome, CVD: cardiovascular disease, DGLA: dihomo-gamma-linolenic acid, DHA: docosahexaenoic acid, EPA: eicosapentaenoic acid, JELIS: Japan EPA Lipid Intervention Study, PUFA: polyunsaturated fatty acid, RAS: renin angiotensin system, TG: triglyceride.

Plasma EPA(Eicosapentaenoic Acid)/AA (Arachidonic Acid) Ratio in Patients With Stage 5 Chronic Kidney Disease: A Novel, Treatable Target?

Plasma EPA(Eicosapentaenoic Acid)/AA (Arachidonic Acid) Ratio in Patients With Stage 5 Chronic Kidney Disease: A Novel, Treatable Target?

Cardiac effects of fish oil in a rat model of streptozotocin-induced diabetes

Background and aimsFish oil (FO) is rich in omega-3 polyunsaturated fatty acids, which have cardio-protective effects. This study aims to evaluate effects of FO in a rat model of streptozotocin (STZ) induced diabetes. Methods and resultsAdults male Wistar rats were assigned to control (4 μl corn oil/g corn oil given by oral gavage), FO (4 μl Menhaden FO/g body weight given by oral gavage), diabetes (DM, 35 mg/kg STZ single intraperitoneal injection, corn oil), and DM + FO groups for 8 weeks. Plasma and cardiac biomarkers of oxidative stress, inflammation, and fibrosis were evaluated. STZ-induced diabetes as indicated by the significant increase in serum levels of glucose and percentage of glycated hemoglobins. FO reduced plasma arachidonic acid (AA) percentage and ratio of AA: docosahexaenoic acid (DHA). Plasma and cardiac levels of total nitrite, endothelin -1 (ET-1), and myeloperoxidase (MPO) increased in the DM group, whereas cardiac activities of catalase and superoxide dismutase (SOD) decreased. FO reduced cardiac nitrite and MPO, and plasma ET-1 levels. FO increased cardiac glutathione, catalase and SOD activities. Levels of thiobarbituric acid substances increased in the FO and DM groups with significant synergism in the DM + FO group. FO prevented cardiac fibrosis associated with DM and decreased cardiac transforming growth factor beta-1and p38 MAP kinases. Cardiac levels of matrix metalloproteinase -2 were significantly elevated in FO and DM + FO groups. ConclusionsFO decreased plasma and cardiac oxidative stress, inflammation and myocardial fibrosis. FO could be used in diabetes to reduce risk and burden of CVDs.

Associations among FADS1 rs174547, eicosapentaenoic acid/arachidonic acid ratio, and arterial stiffness in overweight subjects

We aimed to evaluate the longitudinal interaction effects between the minor allele of FADS1 rs174547 and overweight on n-3 and n-6 long-chain polyunsaturated fatty acid (PUFA) levels and pulse wave velocity (PWV). Plasma PUFA levels were measured via GC-MS, and arterial stiffness was determined as brachial-ankle PWV (ba-PWV) at baseline and after a mean follow-up of 3 years. The FADS1 rs174547 T > C genotype was analyzed. At 3-years of follow-up, after adjustment for age, sex, smoking and drinking, there were interaction effects between the FADS1 rs174547 T > C genotype and baseline BMI on the changes (from baseline) in plasma arachidonic acid (AA) levels, in the eicosapentaenoic acid (EPA)/AA ratio, and in ba-PWV (p for interaction = 0.036, 0.022, and 0.001, respectively). There were smaller increases in AA levels from baseline among normal-weight C allele carriers (n = 112) and overweight TT subjects (n = 47) than among normal-weight TT subjects (n = 91). Overweight C allele carriers (n = 37) showed greater reductions in the plasma EPA/AA ratio and greater increases in ba-PWV than the 3 other populations studied. The minor allele of the FADS1 rs174547 polymorphism is associated with age-related decreases in the EPA/AA ratio and increases in ba-PWV among overweight subjects.

US Family Physicians Overestimate Personal ω-3 Fatty Acid Biomarker Status: Associations with Fatty Fish and ω-3 Supplement Intake

BackgroundThe health benefits of ω-3 (n–3) fatty acids are well established. Only a small percentage of Americans consume the recommended amounts of fatty fish, the main dietary source of ω-3 fatty acids, and most have low ω-3 fatty acid blood concentrations. ObjectiveWe aimed to measure biomarkers of long-chain ω-3 fatty acid (EPA and DHA) status among family physicians, and determine whether having their ω-3 status tested would influence attitudes and patient recommendations. MethodsFamily physicians attending a medical conference (n = 340) completed an ω-3 intake survey and had a finger stick blood sample taken. ω-3 Index, percentage of ω-6 (%n–6) in highly unsaturated fatty acids (HUFAs), and EPA:arachidonic acid (AA) ratio were calculated from whole blood fatty acid profiles. Post-conference, a subsample of participants (n = 100) responded to a survey regarding attitudes and recommendations about ω-3s. ResultsAverage age (mean ± SEM) of participants was 48.0 ± 0.7 y and 59% were women. Average ω-3 Index was 5.2% ± 0.1%, %n–6 in HUFA was 75% ± 0.4%, and EPA:AA ratio was 0.076 ± 0.004. 57% of family physicians reported consuming <2 servings/wk of fatty fish, and 78% reported using ω-3 supplements ≤1/wk. Although 51% believed ω-3 status was in a desirable range, only 5% had an ω-3 Index ≥8%. Biomarkers of ω-3 status were significantly associated with fatty fish intake and supplement use, and were correlated (R2 ranging from 0.59 to 0.77). Physicians who had ω-3 status tested (n = 65) were more likely to agree with statements affirming the health benefits of ω-3 fatty acids and more willing to recommend ω-3 fatty acids to their patients (P = 0.004). ConclusionsBlood concentrations of ω-3 fatty acids in family physicians were below recommendations, and were associated with fatty fish intake and ω-3 supplement use. There was a discrepancy between perceived and actual ω-3 status. Increased awareness of personal ω-3 status among physicians may facilitate patient communication and recommendations about ω-3 fatty acid intake. This trial was registered at clinicaltrials.gov as, NCT03056898.

Age Stratification and Impact of Eicosapentaenoic Acid and Docosahexaenoic Acid to Arachidonic Acid Ratios in Ischemic Stroke Patients.

Aim: We focused on the ratios of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to arachidonic acid (AA) and explored the significance of these ratios relative to clinical characteristics by age in ischemic stroke patients.Methods: We enrolled patients with acute ischemic stroke who underwent radiological investigations and laboratory examinations, including measurement of serum EPA, DHA, and AA levels, and controls. Patients were classified according to age (< 65, 65–74, and ≥ 75 years) and the tertile of EPA/AA and DHA/AA ratios, and clinical aspects were compared with these factors.Results: We analyzed 373 patients (age 70.2 ± 13.4 years; 245 males) and 105 controls. Among stroke patients, patients aged < 65 years had the lowest EPA/AA (0.35 ± 0.23, p = 0.006) and DHA/AA (0.73 ± 0.27, p < 0.001) ratios. Compared with controls, patients aged < 65 years showed lower EPA/AA (vs. 0.49 ± 0.25, p < 0.001) and DHA/AA (vs. 0.82 ± 0.26, p = 0.009) ratios. From logistic regression analysis, the EPA/AA (odds ratio 0.18, 95% confidence interval 0.04–0.81, p = 0.026) and DHA/AA (odds ratio 0.09, 95% confidence interval 0.02–0.33, p < 0.001) ratios were inversely related to patients aged < 65 years. According to age-stratified analyses, we found an association of aortic arch calcification with a lower EPA/AA ratio for patients aged ≥ 75 years and an association of multiple infarctions and cerebral white matter lesions with a lower EPA/AA ratio for patients aged 65–74 years (p < 0.05).Conclusions: The ratios of EPA/AA and DHA/AA could be specific markers for younger stroke patients. The EPA/AA ratio may be related to aortic arch calcification for elderly stroke patients and to multiple infarctions and cerebral white matter disease for middle-aged stroke patients.

Age stratification and impact of eicosapentaenoic and docosahexaenoic to arachidonic acid ratios in ischemic stroke patients

Background: Risk factors for ischemic stroke vary by age, and specific biomarkers for determining risk by age are unknown.

Effects of different dietary DHA:EPA ratios on gonadal steroidogenesis in the marine teleost, tongue sole (Cynoglossus semilaevis).

The present study was conducted to investigate the effects of dietary DHA and EPA on gonadal steroidogenesis in mature females and males, with a feeding trial on tongue sole, a typical marine teleost with sexual dimorphism. Three experimental diets differing basically in DHA:EPA ratio, that is, 0·68 (diet D:E-0·68), 1·09 (D:E-1·09) and 2·05 (D:E-2·05), were randomly assigned to nine tanks of 3-year-old tongue sole (ten females and fifteen males in each tank). The feeding trail lasted for 90 d before and during the spawning season. Fish were reared in a flowing seawater system and fed to apparent satiation twice daily. Compared with diet D:E-0·68, diet D:E-1·09 significantly enhanced the oestradiol production in females, whereas diet D:E-2·05 significantly enhanced the testosterone production in males. In ovaries, diet D:E-1·09 induced highest mRNA expression of follicle-stimulating hormone receptor (FSHR), steroidogenic acute regulatory protein, 17α-hydroxylase (P450c17) and 3β-hydroxysteroid dehydrogenase (3β-HSD). In testes, diet 2·05 resulted in highest mRNA expression of FSHR, cholesterol side-chain cleavage enzyme, P450c17 and 3β-HSD. Fatty acid profiles in fish tissues reflected closely those of diets. Female fish had more gonadal EPA content but less DHA content than male fish, whereas there was a reverse observation in liver. In conclusion, the dietary DHA:EPA ratio, possibly combined with the dietary EPA:arachidonic acid ratio, differentially regulated sex steroid hormone synthesis in mature female and male tongue soles. Females seemed to require more EPA but less DHA for the gonadal steroidogenesis than males. The results are beneficial to sex-specific nutritive strategies in domestic teleost.

The ratio of serum eicosapentaenoic acid to arachidonic acid and riskof cancer death in a Japanese community: The Hisayama Study.

BackgroundWhether the intake of eicosapentaenoic acid (EPA) or arachidonic acid (AA) affects the risk of cancer remains unclear, and the association between the serum EPA:AA ratio and cancer risk has not been fully evaluated in general populations.MethodsA total of 3098 community-dwelling subjects aged ≥40 years were followed up for 9.6 years (2002–2012). The levels of the serum EPA:AA ratio were categorized into quartiles (<0.29, 0.29–0.41, 0.42–0.60, and >0.60). The risk estimates were computed using a Cox proportional hazards model. The same analyses were conducted for the serum docosahexaenoic acid to arachidonic acid (DHA:AA) ratio and individual fatty acid concentrations.ResultsDuring the follow-up period, 121 subjects died of cancer. Age- and sex-adjusted cancer mortality increased with lower serum EPA:AA ratio levels (P trend<0.05). In the multivariable-adjusted analysis, the subjects in the first quartile of the serum EPA:AA ratio had a 1.93-fold (95% confidence interval, 1.15–3.22) greater risk of cancer death than those in the fourth quartile. Lower serum EPA concentrations were marginally associated with higher cancer mortality (P trend<0.11), but the serum DHA or AA concentrations and the serum DHA:AA ratio were not (all P trend>0.37). With regard to site-specific cancers, lower serum EPA:AA ratio was associated with a higher risk of death from liver cancer. However, no such associations were detected for deaths from other cancers.ConclusionsThese findings suggest that decreased level of the serum EPA:AA ratio is a significant risk factor for cancer death in the general Japanese population.

Evaluation of the association between sleep apnea and polyunsaturated fatty acids profiles in patients after percutaneous coronary intervention.

The long-term outcome is poor in patients with sleep apnea and cardiovascular disease. Polyunsaturated fatty acid (PUFA) is also known as an independent predictor for adverse clinical events. However, the profile of PUFA in sleep apnea patients with coronary artery disease (CAD) is still unclear. This study aimed to clarify the association between sleep apnea and PUFA profiles in patients with CAD. Two hundred seventy-four consecutive patients undergoing percutaneous coronary intervention (PCI) were screened for sleep apnea using nocturnal oximetry. Oxygen desaturation index down to 4% (4%ODI) ≥5 was used as an indicator of sleep apnea. Baseline characteristics, including PUFA profiles, were compared between patients with and without sleep apnea. Among 243 enrolled patients, 134 (55%) had sleep apnea. The sleep apnea group included a significantly higher rate of patients with obesity, insulin-requiring diabetes, peripheral artery disease (PAD), and a higher C-reactive protein level than the non-sleep apnea group. The sleep apnea group had a significantly lower eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio than the non-sleep apnea group (0.33 vs. 0.44, respectively, p=0.024). Additionally, EPA value and EPA/AA ratio were significantly correlated with 4%ODI (r=-0.15, p=0.028; r=-0.16, p=0.019, respectively). Results of logistic regression analysis indicated that the comorbidities of obesity, PAD, heart failure and EPA/AA ratio had a significant association with sleep apnea. Our results suggested that patients with sleep apnea who underwent PCI had a lower EPA/AA ratio than those without sleep apnea, and EPA value and EPA/AA ratio were significantly correlated with 4%ODI.

Different effects of γ-linolenic acid (GLA) supplementation on plasma and red blood cell phospholipid fatty acid composition and calcium oxalate kidney stone risk factors in healthy subjects from two race groups with different risk profiles pose questions about the GLA-arachidonic acid-oxaluria metabolic pathway: pilot study.

Fatty acid (FA) composition of phospholipids in plasma and red blood cells (RBC) can influence calciuria, oxaluria and renal stone formation. In this regard, the ratio of arachidonic acid (AA) and its precursor linoleic acid (LA) appears to be important. Administration of γ-linolenic acid (GLA) has been shown to increase the concentration of dihomo-gamma linoleic acid (DGLA) relative to AA indicating that it may attenuate biosynthesis of the latter. Such effects have not been investigated in race groups having difference stone occurrence rates. Black (B) and white (W) healthy males ingested capsules containing linoleic acid (LA) and GLA, for 30days. Plasma and RBC total phospholipid (TPL) FA profiles, serum and 24h urine biomarkers of hypercalciuria and urinary stone risk factors were determined on days 0 and 30. Data were tested for statistical significance using GraphPadInstat version 3.02. Concentration and percentage content of DGLA in plasma TPL increased in W but not in B. Arachidonic acid (AA) did not change in either group. There was no change in calcium excretion in either group but oxalate and citrate excretion increased in W. We suggest that elongation of GLA to DGLA may occur more rapidly than desaturation of DGLA to AA in W and that depressed activity of the enzyme elongase may occur in B. Calciuric and citraturic effects may be dependent on the quantity of LA or on the mass ratio of LA/GLA in the FA supplement. Questions about the mooted DGLA-AA-oxaluria pathway arise. We speculate that there exists a potential for using GLA as a conservative treatment for hypocitraturia. The observation of different responses in B and W indicates that such differences may play a role in stone formation and prevention.

Associations between fatty acids and low-grade inflammation in children from the LISAplus birth cohort study.

Assessing fatty acid (FA) composition in relation to inflammatory markers can shed light on the role of different FA and their metabolism in low-grade inflammation. Existing exploratory studies in children are scarce, and findings inconsistent. We hence aim to analyse associations of FA with common inflammatory markers, high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6), in 10-year-old children. Complete data were available for 958 participants from the 10-year follow-up of the LISAplus (Influence of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood plus the Influence of Traffic Emissions and Genetics) birth cohort study. FA composition was assessed in serum glycerophospholipids. Hs-CRP and IL-6 were categorised into three levels. Associations of FA with inflammatory markers were assessed using multinomial logistic regression, adjusting for potential confounders. Additionally, sex-stratified analyses were carried out. FA exposures associated with significantly higher low-grade inflammation, as indicated by higher hs-CRP or IL-6 levels, included: palmitic acid (PA) (IL-6: P<0.001, 95% confidence interval: 1.30; 2.43), arachidonic acid (AA) (hs-CRP: P=0.002, 1.07; 1.31), n-6 highly unsaturated FA (HUFA) (hs-CRP: P=0.002, 1.06; 1.27), ratio of AA to linoleic acid (AA/LA) (hs-CRP: P<0.001, 1.16; 1.62) and total saturated FA (SFA) (IL-6: P<0.001, 1.77; 3.15). FA exposures associated with reduced levels of inflammatory markers included LA (hs-CRP: P=0.001, 0.84; 0.96; IL-6: P<0.001, 0.69; 0.90) and total polyunsaturated FA (PUFA) (IL-6: P<0.001, 0.57; 0.78). These findings suggest that higher SFA and minor n-6 HUFA, namely PA and AA, are associated with increased low-grade inflammation in children, whereas the major dietary n-6 PUFA and total PUFA are associated with reduced inflammation. Elevated desaturase activity, estimated by the ratio AA/LA, may be associated with higher inflammation, particularly in boys.

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) balance in developmental outcomes

The DHA Intake and Measurement of Neural Development (DIAMOND) trial represents one of only a few studies of the long-term dose-response effects of LCPUFA-supplemented formula feeding during infancy. The trial contrasted the effects of four formulations: 0.00% docosahexaenoic acid (DHA)/0.00% arachidonic acid (ARA), 0.32% DHA/0.64% ARA, 0.64% DHA/0.64% ARA, and 0.96% DHA/0.64% ARA against a control condition (0.00% DHA/0.00% ARA). The results of this trial have been published elsewhere, and show improved cognitive outcomes for infants fed supplemented formulas, but a common finding among many of the outcomes show a reduction of benefit for the highest DHA dose (i.e., 0.96%DHA/0.64% ARA, that is, a DHA: ARA ratio 1.5:1.0). The current paper gathers and summarizes the evidence for the reduction of benefit at this dose, and in an attempt to account for this reduced benefit, presents for the first time data from infants’ red blood cell (RBC) assays taken at 4 and 12 months of age. Those assays indicate that blood DHA levels generally rose with increased DHA supplementation, although those levels tended to plateau as the DHA-supplemented level exceeded 0.64%. Perhaps more importantly, ARA levels showed a strong inverted-U function in response to increased DHA supplementation; indeed, infants assigned to the formula with the highest dose of DHA (and highest DHA/ARA ratio) showed a reduction in blood ARA relative to more intermediate DHA doses. This finding raises the possibility that reduced ARA may be responsible for the reduction in benefit on cognitive outcomes seen at this dose. The findings implicate the DHA/ARA balance as an important variable in the contribution of LCPUFAs to cognitive and behavioral development in infancy.

Effects of dietary arachidonic acid on the reproductive physiology of female Atlantic cod (Gadus morhua L.)

The present study was designed to investigate potential effects of arachidonic acid (ARA) on the reproductive physiology of female Atlantic cod (Gadus morhua L.).Two-year old Atlantic cod of both sexes were equally distributed into eight sea cages after completion of their first spawning in May 2005. Four experimental groups were established and fed diets with different levels of ARA corresponding to 0.5, 1, 2 and 4% of total fatty acid. Ovarian growth and development was documented every month. Fatty acid composition was analysed in ovaries, liver and plasma at the beginning of the experiment, one month prior to spawning, and in spent fish, one month after spawning was completed. Plasma concentrations of estradiol-17β, testosterone and vitellogenin, and ovarian gene transcript levels of steroidogenic acute regulatory protein (star), P450aromatase (cyp19a1a) and 20β-hydroxy steroid dehydrogenase (20bhsd/cbr1) were monitored every month in fish fed the experimental diets and related to oocyte stage. Potential fecundity was calculated based on ovarian samples taken one month before onset of spawning.Ovarian and plasma ARA levels were highly correlated to dietary ARA levels. There was a net accumulation of ARA compared to other essential fatty acids in ovarian tissue that was reflected in a decrease in EPA:ARA ratio. Plasma concentrations of vitellogenin, estradiol-17β and testosterone and key gene transcript levels were affected by dietary ARA and stage of maturation. The results show that ARA has a significant influence on the reproductive physiology of female Atlantic cod.

Nutritional composition of breast milk in Chinese women: a systematic review.

As breast milk is considered nature's best food for infant growth and development, understanding its nutritional composition is crucial for optimising the components of infant formula milk. In this study, we aimed to summarise the available evidence on the nutritional composition of breast milk from Chinese women, in particular, the macronutrients, fatty acids and minerals. We searched PubMed, Embase, and Chinese databases for articles about human breast milk from Chinese women published in English or Chinese between 1999 and 2015. We classified the data in 35 articles from the literature search into three lactation stages: colostral, transitional and mature milk. The content of each component varied greatly during the three lactation stages. Protein content decreased from colostral milk to mature milk (mean±SD, 1.64±0.32 g/dL vs 1.22±0.12 g/dL). In contrast, lipid content increased from colostral milk (2.36±1.17 g/dL) to mature milk (3.39±1.24 g/dL). Colostrum contained more linoleic acid (LA) than transitional and mature milk, while colostrum contained less α-linolenic acid (ALA) than transitional and mature milk. As lactation progressed, the ratios of docosahexaenoic acid (DHA) and arachidonic acid (AA) to total fatty acids decreased while the potassium (K), zinc (Zn), and copper (Cu) concentrations decreased significantly, but their standard deviations were large. Magnesium (Mg) and manganese (Mn) concentrations showed significant differences across the three lactation stages. The stage of lactation was an important factor affecting the nutritional composition of breast milk from Chinese women.